Terminal deletion of the long arm of chromosome 10: a new case with breakpoint in q25.3.

Since the first patient with partial deletion of the long arm of chromosome 10 was described in 1978, another 23 cases have been reported, with the breakpoint ranging from 10q23.3-26.2. To contribute further to the delineation of the monosomy 10qter syndrome, we describe a female child who, at age 3 6/12 years, was diagnosed with a de novo deletion of the long arm of chromosome 10, with a breakpoint in 10q25.3. The phenotypic manifestations in this child are compatible with those of previously reported cases. However, in contrast to most other patients, we found a moderate expression of the syndrome, with no genitourinary or cardiac malformations and with only mild retardation. Based on our observations and those of others, we conclude that a typical craniofacial appearance and varying degrees of psychomotor retardation are always found in patients with 10q- syndrome.